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5 Things To Know About Colon Cancer Prevention and Screening

March 18, 2024
by Rachel Martin

Colorectal cancer is the third most common cancer in the United States, and more than 150,000 people will be diagnosed with colorectal cancer this year. For Colon Cancer Awareness Month, Xavier Llor, MD, PhD, professor of medicine (digestive diseases) and director of the Gastrointestinal (GI) and Pancreatic Cancer Prevention Program, shared some things everyone should know about colorectal cancer.

1. Early-onset colorectal cancer is on the rise.

Over the last 40 years, there has been a decline in colon cancer overall; however, since 2011, there has been a very steady, significant increase year over year in colorectal cancers in younger individuals (under age 50). “We’re seeing a cohort effect, where everyone born from the early 1960s on carry a higher risk for colorectal cancers,” said Llor. “We’re seeing so many young people with healthy dietary habits, who don’t use tobacco, and who test negative for a genetic defect, and yet they have colon cancer at age 35. This trend is really worrisome.”

Researchers are still trying to understand why this trend is occurring. “It’s likely environmental factors, like the air we breathe or what we eat and drink. Genetics don’t change that fast,” said Llor. “This is the multi-million-dollar question in colon cancer prevention right now.”

2. Screening for average-risk patients now starts at age 45.

In response to the rise in colon cancer among younger people, the United States Preventative Services Task Force (USPTF) has endorsed screening for average-risk patients at age 45. Unfortunately, many younger adults are still not getting screened.

“Getting screened early could save your life,” Llor said.

Risk factors for colon cancer include lifestyle factors, like weight, diet, exercise, and substance use, along with genetic factors. People at higher risk of colon cancer should start screenings at age 40.

3. Patients with certain genetic diseases carry a higher risk of colon cancer

Research shows that approximately 5-6% of colorectal cancers are associated with a genetic factor. Yale’s Gastrointestinal (GI) and Pancreatic Cancer Prevention Program, which Llor co-leads, helps diagnose, screen, and coordinate care for patients with genetic syndromes that put them at higher risk for colorectal and other GI cancers.

“Navigating the healthcare system in this country is extremely complicated. It can be a huge burden for patients to manage different doctor visits and screenings, yet we know this kind of diligent follow-up is especially important for high-risk patients,” said Llor. “Our main goal is to provide the care coordination patients need to ease the burden for patients while comprehensively working with them to help them prevent cancer.”

Patients who may be at a higher risk for hereditary cancer include:

  • A personal or family history of early-onset cancer (younger than 45-50 years)
  • Multiple family members on the same side of the family with the same or related cancers
  • An individual or family member with a diagnosis of more than one type of cancer
  • A personal or family history of colorectal, endometrial, or breast cancer
  • A personal or family history of ovarian or pancreatic cancer at any age
  • A personal or family history of a rare type of cancer/tumor

4. There are multiple screening options for patients.

For many years, colonoscopies were thought of as the only colorectal cancer screening option. In recent years, organizations like the USPTF, American Cancer Society, and American Gastroenterological Association have encouraged the use of stool-based tests for certain patients.

“Now, clinicians can be smart about stratifying patients by risk and offering patients choices that work best for them,” said Llor. “Each test carries different benefits and risks. Ultimately, the best test is the one that gets done.”

Providers can now offer patients the choice between colonoscopies or stool-based tests. Each test carries different benefits and different risks.

To help providers determine which test is suitable for each patient, Yale developed a colon cancer screening pathway in Epic. The pathway provides health care providers with details about the sensitivities and risks of each screening option. It includes easy-to-share educational resources for patients so that they can understand the different screening options available to them. Providers can also order tests directly from the pathway.

5. Not all polyps become cancerous – but more research is needed

More than a third of patients over 50 who have a colonoscopy will have polyps, which are abnormal growths on the inner walls of the colon or rectum. A very small percentage of polyps progress into cancer.

“We still don’t understand which polyps will progress into cancer or why, and only in the case of the advanced ones do we have a high level of certainty they can progress to cancer,” said Llor. He and his colleagues are part of a multi-site study funded by the National Cancer Institute that is looking into this question. Specifically, the research aims to understand if a patient with one or two small tubular adenomas (a specific type of polyp) has a higher risk of colon cancer. Current guidelines recommend more frequent colonoscopies for patients with this finding. This research may help understand if these more frequent screenings are necessary for patients.

Since forming one of the nation’s first sections of hepatology more than 75 years ago and then gastroenterology nearly 70 years ago, Yale School of Medicine’s Section of Digestive Diseases has had an enduring impact on research and clinical care in gastrointestinal and liver disorders. To learn more about their work, visit Internal Medicine: Digestive Diseases.

Submitted by Rachel Martin on March 13, 2024